In order to learn more about where and how youth obtain alcohol and how the source of alcohol, drinking context, drinking behaviors, and community-level alcohol policies and enforcement are related, we propose to undertake a study that combines qualitative and quantitative methods. Specifically we will undertake (a) in- depth semi-structured interviews with 50 young drinkers identified from an ongoing a longitudinal survey of youth ages 13 to 16 from geographically diverse California cities, and (b) expand the questionnaire for the final wave of that survey by adding detailed questions on youth access to alcohol and drinking context that will be developed from the qualitative interviews. The proposed research has three specific aims: 1. To obtain a detailed qualitative description of the social and commercial pathways through which youth obtain alcohol and the context within which alcohol is consumed. To address this aim we will undertake semi-structured interviews with young drinkers identified in an ongoing survey. 2. To develop a comprehensive set of questions to address sources of alcohol and of drinking contexts based on the data from the qualitative component of the proposed research. These items will ask details about issues such as how alcohol was obtained on the last drinking occasion, who provided the alcohol (e.g., age, gender, relationship to the drinker), where drinking took place, and how much was consumed. 3. To obtain population data on sources of alcohol and drinking contexts. To achieve this aim, the measures developed from the quantitative study will be applied in a large community survey to investigate (a) prevalence estimates for use of specific sources of alcohol and drinking in specific contexts, (b) how are the use of different sources of alcohol and drinking in specific contexts related to alcohol consumption patterns, and (c) how individual and community characteristics (e.g., local policies and enforcement levels, median income, neighborhood disadvantage, and other population characteristics) relate to the use of different social and commercial sources for alcohol by youth. PUBLIC HEALTH RELEVANCE: Findings from this study will (1) will inform prevention efforts designed to limit youth access to alcohol by identifying where and how youth obtain alcohol both generally and in specific communities, and (2) inform community-based policy and enforcement efforts by highlighting how youth access to alcohol and drinking contexts are related to existing policies. Gaining an understanding of how youth access alcohol and how these sources relate to drinking behaviors and contexts will allow the development of more effective policies and programs and allow interventions to be more efficiently targeted at at-risk groups.